Adherence to Islam is a global phenomenon: Muslims predominate in some 30 to 40 countries, from the Atlantic eastward to the Pacific and along a belt that stretches across northern Africa into Central Asia and south to the northern regions of the Indian subcontinent. Arabs account for fewer than one-fifth of all Muslims, more than half of whom live east of Karachi, Pak. Despite the absence of large-scale Islamic political entities, the Islamic faith continues to expand, by some estimates faster than any other major religion.